Spectroscopy of the near-infrared afterglow of GRB 050904 at z = 6.3

2006 ◽  
Vol 2 (14) ◽  
pp. 264-264
Author(s):  
Nobuyuki Kawai
Keyword(s):  
Early Universe ◽  
Precise Measurement ◽  
Near Infrared ◽  
Absorption Lines ◽  
Heavy Elements ◽  
Star Forming ◽  
Long Wavelength ◽  
Faint Object ◽  
The Galaxy ◽  
Sharp Cutoff

AbstractWe present the optical/NIR spectrum of the afterglow of GRB 050904 obtained with the Faint Object Camera And Spectrograph on the Subaru 8.2m telescope taken 3.4 days after the burst. It is, as of June 2006, the only GRB with a known redshift larger than 6. The spectrum shows a clear continuum at the long wavelength end of the spectrum with a sharp cutoff at around 900nm due to Lyα absorption at a redshift of 6.3 with a damping wing. Little flux is present in the waveband shortward of the Lyα break. A system of absorption lines of heavy elements at redshift z = 6.295±0.002 were also detected, yielding a precise measurement of the largest known redshift of a GRB. Analysis of the silicon and sulphur absorption lines suggests a dense environment around the GRB with the metallicity larger than 0.1 solar, providing unique information on the galaxy and star forming region at z>6. This observation has shown that GRB is a powerful probe of the early universe.

scholarly journals Planck’s dusty GEMS

2018 ◽  
Vol 620 ◽  
pp. A60 ◽  
Author(s):  
R. Cañameras ◽  
N. P. H. Nesvadba ◽  
M. Limousin ◽  
H. Dole ◽  
R. Kneissl ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
Infrared Imaging ◽  
High Redshift ◽  
Dust Emission ◽  
Galaxy Cluster ◽  
Star Forming ◽  
The Galaxy ◽  
Mass Outflow ◽  
Gas Accretion

We report the discovery of a molecular wind signature from a massive intensely star-forming clump of a few 109 M⊙, in the strongly gravitationally lensed submillimeter galaxy “the Emerald” (PLCK_G165.7+49.0) at z = 2.236. The Emerald is amongst the brightest high-redshift galaxies on the submillimeter sky, and was initially discovered with the Planck satellite. The system contains two magnificient structures with projected lengths of 28.5″ and 21″ formed by multiple, near-infrared arcs, falling behind a massive galaxy cluster at z = 0.35, as well as an adjacent filament that has so far escaped discovery in other wavebands. We used HST/WFC3 and CFHT optical and near-infrared imaging together with IRAM and SMA interferometry of the CO(4–3) line and 850 μm dust emission to characterize the foreground lensing mass distribution, construct a lens model with LENSTOOL, and calculate gravitational magnification factors between 20 and 50 in most of the source. The majority of the star formation takes place within two massive star-forming clumps which are marginally gravitationally bound and embedded in a 9 × 1010 M⊙, fragmented disk with 20% gas fraction. The stellar continuum morphology is much smoother and also well resolved perpendicular to the magnification axis. One of the clumps shows a pronounced blue wing in the CO(4–3) line profile, which we interpret as a wind signature. The mass outflow rates are high enough for us to suspect that the clump might become unbound within a few tens of Myr, unless the outflowing gas can be replenished by gas accretion from the surrounding disk. The velocity offset of –200 km s−1 is above the escape velocity of the clump, but not that of the galaxy overall, suggesting that much of this material might ultimately rain back onto the galaxy and contribute to fueling subsequent star formation.

scholarly journals Quasar Sightline and Galaxy Evolution (QSAGE) survey – I. The galaxy environment of O vi absorbers up to z = 1.4 around PKS 0232−04

2019 ◽  
Vol 486 (1) ◽  
pp. 21-41 ◽  
Author(s):  
R M Bielby ◽  
J P Stott ◽  
F Cullen ◽  
T M Tripp ◽  
J N Burchett ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Near Infrared ◽  
Hubble Space Telescope ◽  
High Redshift ◽  
Star Forming ◽  
The Galaxy ◽  
Circumgalactic Medium ◽  
Galaxy Environment ◽  
Using Data ◽  
Galaxy Population

ABSTRACT We present the first results from a study of O vi absorption around galaxies at z < 1.44 using data from a near-infrared grism spectroscopic Hubble Space Telescope Large Programme, the Quasar Sightline and Galaxy Evolution (QSAGE) survey. QSAGE is the first grism galaxy survey to focus on the circumgalactic medium at z ∼ 1, providing a blind survey of the galaxy population. The galaxy sample is H α flux limited (f(H α) > 2 × 10−17 erg s−1 cm−2) at 0.68 < z < 1.44, corresponding to ≳0.2–0.8 M⊙ yr−1. In this first of 12 fields, we combine the galaxy data with high-resolution STIS and COS spectroscopy of the background quasar to study O vi in the circumgalactic medium. At z ∼ 1, we find O vi absorption systems up to b ∼ 350 kpc (∼4Rvir) from the nearest detected galaxy. Further, we find ${\sim }50{{\ \rm per\ cent}}$ of ≳1 M⊙ yr−1 star-forming galaxies within 2Rvir show no associated O vi absorption to a limit of at least N(O vi) = 1013.9 cm−2. That we detect O vi at such large distances from galaxies and that a significant fraction of star-forming galaxies show no detectable O vi absorption disfavours outflows from ongoing star formation as the primary medium traced by these absorbers. Instead, by combining our own low- and high-redshift data with existing samples, we find tentative evidence for many strong (N(O vi) > 1014 cm−2) O vi absorption systems to be associated with M⋆ ∼ 109.5–10 M⊙ mass galaxies (Mhalo ∼ 1011.5–12 M⊙ dark matter haloes), and infer that they may be tracing predominantly collisionally ionized gas within the haloes of such galaxies.

scholarly journals Euclid preparation

2020 ◽  
Vol 642 ◽  
pp. A192 ◽  
Author(s):  
◽  
V. Guglielmo ◽  
R. Saglia ◽  
F. J. Castander ◽  
A. Galametz ◽  
...  
Keyword(s):  
Near Infrared ◽  
Current Knowledge ◽  
High Redshift ◽  
Stage Iv ◽  
Weak Lensing ◽  
Success Rates ◽  
Spectroscopic Measurements ◽  
Star Forming ◽  
The Galaxy ◽  
Stellar Masses

The Complete Calibration of the Colour–Redshift Relation survey (C3R2) is a spectroscopic effort involving ESO and Keck facilities designed specifically to empirically calibrate the galaxy colour–redshift relation – P(z|C) to the Euclid depth (iAB = 24.5) and is intimately linked to the success of upcoming Stage IV dark energy missions based on weak lensing cosmology. The aim is to build a spectroscopic calibration sample that is as representative as possible of the galaxies of the Euclid weak lensing sample. In order to minimise the number of spectroscopic observations necessary to fill the gaps in current knowledge of the P(z|C), self-organising map (SOM) representations of the galaxy colour space have been constructed. Here we present the first results of an ESO@VLT Large Programme approved in the context of C3R2, which makes use of the two VLT optical and near-infrared multi-object spectrographs, FORS2 and KMOS. This data release paper focuses on high-quality spectroscopic redshifts of high-redshift galaxies observed with the KMOS spectrograph in the near-infrared H- and K-bands. A total of 424 highly-reliable redshifts are measured in the 1.3 ≤ z ≤ 2.5 range, with total success rates of 60.7% in the H-band and 32.8% in the K-band. The newly determined redshifts fill 55% of high (mainly regions with no spectroscopic measurements) and 35% of lower (regions with low-resolution/low-quality spectroscopic measurements) priority empty SOM grid cells. We measured Hα fluxes in a 1.″2 radius aperture from the spectra of the spectroscopically confirmed galaxies and converted them into star formation rates. In addition, we performed an SED fitting analysis on the same sample in order to derive stellar masses, E(B − V), total magnitudes, and SFRs. We combine the results obtained from the spectra with those derived via SED fitting, and we show that the spectroscopic failures come from either weakly star-forming galaxies (at z <  1.7, i.e. in the H-band) or low S/N spectra (in the K-band) of z >  2 galaxies.

scholarly journals ALMA Deep Field in SSA22

2020 ◽  
Vol 640 ◽  
pp. L8 ◽  
Author(s):  
Hideki Umehata ◽  
Ian Smail ◽  
A. M. Swinbank ◽  
Kotaro Kohno ◽  
Yoichi Tamura ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Near Infrared ◽  
Formation Rate ◽  
Stellar Mass ◽  
Star Forming ◽  
Submillimeter Galaxies ◽  
The Galaxy ◽  
Deep Survey ◽  
Multi Wavelength

Deep surveys with the Atacama Large Millimeter Array (ALMA) have uncovered a population of dusty star-forming galaxies which are faint or even undetected at optical to near-infrared wavelengths. Their faintness at short wavelengths makes the detailed characterization of the population challenging. Here we present a spectroscopic redshift identification and a characterization of one of these near-infrared-dark galaxies discovered by an ALMA deep survey. The detection of [C I](1–0) and CO(4–3) emission lines determines the precise redshift of the galaxy, ADF22.A2, to be z = 3.9913 ± 0.0008. On the basis of a multi-wavelength analysis, ADF22.A2 is found to be a massive, star-forming galaxy with a stellar mass of M∗ = 1.1−0.6+1.3 × 1011 M⊙ and SFR = 430−150+230 M⊙ yr−1. The molecular gas mass was derived to be M(H2)[CI] = (5.9 ± 1.5)×1010 M⊙, indicating a gas fraction of ≈35%, and the ratios of L[CI](1−0)/LIR and L[CI](1−0)/LCO(4−3) suggest that the nature of the interstellar medium in ADF22.A2 is in accordance with those of other bright submillimeter galaxies. The properties of ADF22.A2, including the redshift, star-formation rate, stellar mass, and depletion time scale (τdep ≈ 0.1−0.2 Gyr), also suggest that ADF22.A2 has the characteristics expected for the progenitors of quiescent galaxies at z ≳ 3. Our results demonstrate the power of ALMA contiguous mapping and line scan, which help us to obtain an unbiased view of galaxy formation in the early Universe.

scholarly journals Physics of a clumpy lensed galaxy at z = 1.6

2018 ◽  
Vol 619 ◽  
pp. A15 ◽  
Author(s):  
M. Girard ◽  
M. Dessauges-Zavadsky ◽  
D. Schaerer ◽  
J. Richard ◽  
K. Nakajima ◽  
...  
Keyword(s):  
Star Formation ◽  
Gravitational Lensing ◽  
Near Infrared ◽  
High Redshift ◽  
Formation Rate ◽  
Far Infrared ◽  
Rotating Disk ◽  
Cluster Galaxy ◽  
Star Forming ◽  
The Galaxy

Observations have shown that massive star-forming clumps are present in the internal structure of high-redshift galaxies. One way to study these clumps in detail with a higher spatial resolution is by exploiting the power of strong gravitational lensing which stretches images on the sky. In this work, we present an analysis of the clumpy galaxy A68-HLS115 at z = 1.5858, located behind the cluster Abell 68, but strongly lensed by a cluster galaxy member. Resolved observations with SINFONI/VLT in the near-infrared (NIR) show Hα, Hβ, [NII], and [OIII] emission lines. Combined with images covering the B band to the far-infrared (FIR) and CO(2–1) observations, this makes this galaxy one of the only sources for which such multi-band observations are available and for which it is possible to study the properties of resolved star-forming clumps and to perform a detailed analysis of the integrated properties, kinematics, and metallicity. We obtain a stability of υrot/σ0 = 2.73 by modeling the kinematics, which means that the galaxy is dominated by rotation, but this ratio also indicates that the disk is marginally stable. We find a high intrinsic velocity dispersion of 80 ± 10 km s−1 that could be explained by the high gas fraction of fgas = 0.75 ± 0.15 observed in this galaxy. This high fgas and the observed sSFR of 3.12 Gyr−1 suggest that the disk turbulence and instabilities are mostly regulated by incoming gas (available gas reservoir for star formation). The direct measure of the Toomre stability criterion of Qcrit = 0.70 could also indicate the presence of a quasi-stable thick disk. Finally, we identify three clumps in the Hα map which have similar velocity dispersions, metallicities, and seem to be embedded in the rotating disk. These three clumps contribute together to ∼40% on the SFRHα of the galaxy and show a star formation rate density about ∼100 times higher than HII regions in the local Universe.

scholarly journals “E+A” Galaxies: Environment and Evolution

1999 ◽  
Vol 186 ◽  
pp. 125-131
Author(s):  
Ann I. Zabludoff
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Morphological Characteristics ◽  
Absorption Lines ◽  
Evolutionary Track ◽  
Star Forming ◽  
Blue Star ◽  
The Galaxy ◽  
Important Approach ◽  
Critical Link

One important approach to the study of galaxy evolution is to identify those galaxies whose spectral and/or morphological characteristics suggest that they are in transition. For example, “E+A” galaxies, which have strong Balmer absorption lines and no significant [OII] emission, are generally interpreted as post-starburst galaxies in which the star formation ceased within the last ~ Gyr (Fig. 1). This transition between a star forming and non-star forming state is a critical link in any galaxy evolution model in which a blue, star forming disk galaxy evolves into a SO or elliptical. Another possible evolutionary track is that the star formation in an “E+A” resumes at some later time, if enough gas remains in the galaxy after its starburst ends. Given this ambiguity, it is important to investigate (1) the environment's role in “E+A” evolution, (2) the stellar and gas morphologies of “E+A”s, (3) the likely progenitors of “E+A”s, and (4) how common the “E+A” phase is in the evolution of galaxies.

scholarly journals A multiwavelength study of a massive, active galaxy at z ∼ 2: coupling the kinematics of the ionized and molecular gas

2019 ◽  
Vol 489 (1) ◽  
pp. 681-698 ◽  
Author(s):  
Federica Loiacono ◽  
Margherita Talia ◽  
Filippo Fraternali ◽  
Andrea Cimatti ◽  
Enrico M Di Teodoro ◽  
...  
Keyword(s):  
Near Infrared ◽  
Molecular Gas ◽  
Star Forming ◽  
Systemic Velocity ◽  
Star Formation Activity ◽  
The Galaxy ◽  
Central Regions ◽  
Outflow Rate ◽  
Gas Consumption ◽  
Fisher Relation

ABSTRACTWe report a multiwavelength study of the massive ($M_{\star } \gtrsim 10^{11} \rm {M}_{\odot }$), z ∼ 2 star-forming galaxy GMASS 0953, which hosts an obscured AGN. We combined near-infrared observations of the GNIRS, SINFONI and KMOS spectrographs to study the kinematics of the [O  iii] λ5007 and H α emission lines. Our analysis shows that GMASS 0953 may host an ionized disc extending up to 13 kpc, which rotates at a velocity of $V_{\rm {ion}} = 203^{+17}_{-20}$  km s−1 at the outermost radius. Evidence of rotation on a smaller scale (R ∼ 1 kpc) arises from the CO(J = 6–5) line. The central velocity $V_{\rm {CO}} = 320^{+ 92}_{-53}$  km s−1 traced by the molecular gas is higher than Vion, suggesting that the galaxy harbours a multiphase disc with a rotation curve that peaks in the very central regions. The galaxy appears well located on the z = 0 baryonic Tully–Fisher relation. We also discuss the possibility that the [O  iii] λ5007 and H α velocity gradients are due to a galactic-scale wind. Besides, we found evidence of an AGN-driven outflow traced by a broad blueshifted wing affecting the [O  iii] λ5007 line, which presents a velocity offset Δv = −535 ± 152  km s−1 from the systemic velocity. Because of the short depletion time-scale (τdep ∼ 108 yr) due to gas ejection and gas consumption by star formation activity, GMASS 0953 may likely evolve into a passive galaxy. However, the role of the AGN in depleting the gas reservoir of the galaxy is quite unclear because of the uncertainties affecting the outflow rate.

scholarly journals Luminosity Dependent Evolution of Lyman Break Galaxies from redshift 5 to 3

2006 ◽  
Vol 2 (S235) ◽  
pp. 364-365
Author(s):  
I Iwata ◽  
K. Ohta ◽  
N. Tamura ◽  
M. Akiyama ◽  
K. Aoki ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Early Universe ◽  
Major Step ◽  
Field Surveys ◽  
Star Forming ◽  
Lyman Break Galaxies ◽  
The Galaxy ◽  
The Many ◽  
Relationship Of ◽  
The Relationship

AbstractThe development of large ground-based telescopes and sensitive large format detectors, as well as the develepment of various techniques for the selection of high-z galaxies enabled us to construct large samples of galaxies in the early universe, as reported in the many contributions in this proceedings. The next major step for the comprehensive understanding of the galaxy evolution would be to explore the relationship of galaxies selected with different criteria at different epochs and find links between them. In this contribution we present the properties of Lyman break galaxies (LBGs) at z ~ 5 obtained by deep and wide blank field surveys, and through the comparison with samples at lower redshift ranges we discuss the evolution of star-forming galaxies in the early universe.

scholarly journals The nuclear region of NGC 613 – I. Multiwavelength analysis

2020 ◽  
Vol 492 (4) ◽  
pp. 5121-5140 ◽  
Author(s):  
Patrícia da Silva ◽  
R B Menezes ◽  
J E Steiner
Keyword(s):  
Supernova Remnants ◽  
Near Infrared ◽  
H Ii Regions ◽  
Nuclear Region ◽  
Radio Telescopes ◽  
X Ray ◽  
Star Forming ◽  
Dust Extinction ◽  
The Galaxy ◽  
Variable Point

ABSTRACT In this paper, we report a detailed study with a variety of data from optical, near-infrared, X-ray, and radio telescopes of the nuclear region of the galaxy NGC 613 with the aim of understanding its complexity. We detected an extended stellar emission in the nucleus that, at first, appears to be, in the optical band, two stellar nuclei separated by a stream of dust. The active galactic nucleus (AGN) is identified as a variable point-like source between these two stellar components. There is a central hard X-ray emission and an extended soft X-ray emission that closely coincides with the ionization cone, as seen in the [O iii]λ5007 emission. The centroid of the [O i]λ6300 emission does not coincide with the AGN, being shifted by 0.24 arcsec towards the ionization cone; this shift is probably caused by a combination of differential dust extinction together with emission and reflection in the ionization cone. The optical spectra extracted from the central region are typical of low-ionization nuclear emission-line regions. We also identify 10 H ii regions, eight of them in a star-forming ring that is visible in Br γ, [Fe ii]λ16436, and molecular CO(3-2) images observed in previous studies. Such a ring also presents weak hard X-ray emission, probably associated with supernova remnants, not detected in other studies. The position of the AGN coincides with the centre of a nuclear spiral (detected in previous works) that brings gas and dust from the bar to the nucleus, causing the high extinction in this area.

scholarly journals A massive stellar bulge in a regularly rotating galaxy 1.2 billion years after the Big Bang

Science ◽  
2021 ◽  
Vol 371 (6530) ◽  
pp. 713-716 ◽  
Author(s):  
Federico Lelli ◽  
Enrico M. Di Teodoro ◽  
Filippo Fraternali ◽  
Allison W. S. Man ◽  
Zhi-Yu Zhang ◽  
...  
Keyword(s):  
Early Universe ◽  
Galaxy Formation ◽  
Rotating Disk ◽  
Big Bang ◽  
Starburst Galaxy ◽  
Rotating Disks ◽  
Star Forming ◽  
The Galaxy ◽  
Central Bulge ◽  
Gas Accretion

Cosmological models predict that galaxies forming in the early Universe experience a chaotic phase of gas accretion and star formation, followed by gas ejection due to feedback processes. Galaxy bulges may assemble later via mergers or internal evolution. Here we present submillimeter observations (with spatial resolution of 700 parsecs) of ALESS 073.1, a starburst galaxy at redshift z≃5 when the Universe was 1.2 billion years old. This galaxy’s cold gas forms a regularly rotating disk with negligible noncircular motions. The galaxy rotation curve requires the presence of a central bulge in addition to a star-forming disk. We conclude that massive bulges and regularly rotating disks can form more rapidly in the early Universe than predicted by models of galaxy formation.

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